Bill, maybe Charlie suggested the idea. CBM was an important consultant at Yale.
As for why Raynor never repeated the concept, he didn't have the opportunity: he passed away, before Yale even opened IIRC.
Raynor died in 1926. The planning for Yale began in 1923. Yeamans Hall, Fox Chapel, Blue Mound, Wailee, CC of Charleston and Fishers Island all were built later. Raynor did not conceive of a two-part green at Yale nor any of these subsequent courses... Charles Banks, who was with him at Yale, finished several of the courses above, and built about a dozen of his own Biarritz holes, all with fairway-height approaches. Banks wrote far more than Raynor, yet he never wrote about a two-section putting surface at Yale, did he?
The idea that Macdonald came up with the concept is really far-fetched. Call him pompous if you want; he was convinced that his ideal holes were so good that there was no room for improvement. Macdonald wrote about Yale and never talked about a two-sectioned green. If you know anything about CBM, you can be certain that he would have taken full ownership of this MAJOR deviation to the design and play of the Biarritz. This would have probably received a full chapter in Scotland's Gift... Yet all he talks about is how much land had to be cleared, how much it cost, and what a great test of golf the course presented.
What you and Pat seem to fail to grasp is that a Biarritz hole is ALL about creating a difficult approach, an approach flanked by sand or water hazards. When you cut holes in the approach and call it putting surface, you create a nice, mid-range par three, but it is no longer a Biarritz. There is no more long one shotter on the course; no more test of a player's ability to hit a low, running tee shot. If Sven is disappointed when he has to play to a front pin, imagine what Macdonald would have said? He must be spinning in his grave!